The deal lands Crucell a €10m payment, with further milestone payments of up to €66.5m and a percentage of Sanofi's sales of the product. Crucell has been working on the antibody cocktail for several years, having used its MAbstract drug target discovery technology to come up with the combination of two human anti-rabies antibodies. While there is no treatment for rabies once symptoms have appeared, lethal rabies can be prevented by post-exposure prophylaxis via the combined administration of a rabies vaccine and rabies immune globulin (RIG). Neither vaccine nor RIG is effective if administered alone. RIG, however, is in short supply (particularly in Asian countries where rabies is a common threat), and carries certain safety concerns as it originates from human or equine blood. Crucell has tackled this need by developing a combination antibody product that can be produced using its popular PER.C6 technology. Data from the company's First-in-Man Phase I study presented in October, showed that the antibody cocktail was well tolerated, with results comparable to current immunoglobulin products. The company's programme has been granted fast track status by the US Food and Drug Administration's (FDA) Department of Health and Human Services, with Phase II clinical trials expected to start during the first half of this year. Crucell has also contacted DSM Biologics its alliance partner for the PER.C6 technology platform, for the process validation and manufacturing of antibody batches for Phase III clinical efficacy studies. Under the terms of the Sanofi Pasteur agreement, Crucell will continue to perform development activities related to the rabies cocktail treatment. The Dutch firm will also be responsible for manufacturing the final product, and will retain exclusive distribution rights in Europe, co-exclusive distribution rights in China, and the rights to sell to supranational organisations such as UNICEF. The company has forecast peak sales of the antibody cocktail to exceed $300m, and claims the product has the potential to replace the traditional serum-based products that are the mainstay of current rabies treatment.